This ignition system can be scoped, fairly easy, suggest having that done! Now if you are just going to throw parts on it start with a new complete distributor and ignition coil. 'Scanner' will also do misfire test and show which cylinder(s) are affected.
Transmission, NO!!!

may need to change the coil pack out with new one - and make sure plugs have correct gap setting on them - a transmission has nothing to do with a engine misfiring, whole different ballgame - hope this helps